Extensible step

ABSTRACT

An extensible step particularly suited for use with recreational vehicles such as campers, mobile homes, trailers and the like. The step is characterized by a base frame mounting the step beneath the doorway of a recreational vehicle, a horizontally displaceable tread supported within the base frame, and a remotely controlled prime mover coupled with the tread for selectively imparting horizontally directed, substantially rectilinear motion to the tread for repositioning the tread relative to a stowed position beneath the vehicle and an operative position laterally extended therefrom.

United States Patent [1 1 Bridges Nov. 13, 1973 EXTENSIBLE STEP [76]Inventor: Ralph F. Bridges, 6838 East Floral, Selma, Calif.

[22] Filed: Apr. 13, 1972 [21] Appl. No.: 243,815

[52] U.S. Cl. 280/166 [51] Int. Cl. 1360: 3/02 [58] Field of Search280/166, 164;

[56] References Cited UNITED STATES PATENTS 2,797,104 6/1957 Drobney28'0/166 2,118,557 5/1938 Hamilton 280/166 1,180,215 4/1916 Weiss2801166 3,008,533 11/1961 Haberle 280/166 1,054,430 2/1913 Major 105/444Primary Examiner-Robert R. Song Attorney-Herbert A. Huebner et al.

[57] ABSTRACT An extensible step particularly suited for use withrecreational vehicles such as campers, mobile homes, trailers and thelike. The step is characterized by a base frame mounting the stepbeneath the doorway of a recreational vehicle, a horizontallydisplaceable tread supported within the base frame, and a remotelycontrolled prime mover coupled with the tread for selectively impartinghorizontally directed, substantially rectilinear motion to the tread forrepositioning the tread relative to a stowed position beneath thevehicle and an operative position laterally extended therefrom.

3 Claims, 7 Drawing Figures PATENTEU NUY 13 I975 SHEET 10F 2 1EXTENSIBLE srnr BACKGROUND OF THE INVENTION The invention relates tosteps for vehicles and more particularly to a remotely controlled,extensible step particularly suited for use with a recreational vehicleof the type including campers, mobile homes, trailers and the like.

As is well unserstood, recreational vehicles, such as campers, mobilehomes, trailers and the like are supported upon wheels which facilitatetheir being transported along highways, dirt roads, and often overrelatively rough terrain. It heretofore has been common practice toprovide a step suspended between the floor of the vehicle and theground, or other supporting surfaces, for accommodating entry into thevehicle. In certain instances the steps have been weldedin a fixedposition to the frame of the vehicle. While such steps can be utilizedby vehicles employed on smooth roadways, these steps normally extendfrom the vehicle and thus are hazardous, impractical, and often aredeformed and even destroyed upon impact of boulders,'trees, and thelike, as the vehicle is moved over terrain of the type frequentlytraversed by such vehicles.

In order to overcome the noted deficiencies of rigidly supported steps,various attempts have been made to provide steps which are removableduring periods in which the vehicle is being transported to and from aplace of use, and thereafter mounted in an operative position when thevehicle is at rest. Included within this type of step are stools andladders which are employed as they rest upon the ground and then arestowed and transported within the vehicle, and pivotal steps which areattached to the vehicle and are repositionable rela tive thereto.

Of course, none of these types of steps provides an adequate solution tothe problem of providing a step employable with such vehicles since, ineach instance, an operator must set-up" as well as stow the step whilehe is on the ground outside the vehicle. This inadequacy becomesparticularly critical where the operator must gain access to the vehiclewhile the step is stowed aboard the vehicle. As can be appreciated, theaged, the infirmed, and the crippled frequently cannot'accomplish thisfeat. I

Therefore, it is apparent that there currently exists a need for anextensible step for aiding in gaining access to vehicles of the typeincluding campers, mobile homes, trailers and the like which can bestowed and repositioned into an operative configuration through aselective energization of a control system having a selector switchmounted for manipulation aboard the vehicle.

OBJECTS AND SUMMARY OF THE INVENTION It is therefore an object of theinstant invention to provide a remotely controlled extensible step.

It is another object to provide an improved extensible step for use withrecreational vehicles.

It is another object to provide an extensible step which can besupported beneath an operating vehicle and laterally extended therefrominto an operative configuration, through a manipulation of a remotelypositioned selector switch.

It is another object to provide a simple, economical, and practical stephaving particular utility with recreational vehicles, such as campers,mobile homes, trailers and the like and controlled through an electricalcircuit powered by a source of electrical energy.

It is another object of the instant invention to provide in a remotelycontrolled, extensible step of the type to be mounted beneath thedoorways of recreational vehicles, a tread reconfigurable from a stowedconfiguration aboard the vehicle to an operable configuration laterallyextended therefrom whereby an operator located aboard the vehicle canreconfigure the step withlinkage for imparting substantially rectilinearmotion to the beams, whereby the tread is alternately deployed andthereafter stowed aboard the vehicle, and remote control means locatedaboard the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmented, perspectiveview of a vehicle of a type having suspended therefrom an extensiblestep which embodies the principles of the instant invention.

FIG. 2 is a plan view of the step illustrated in FIG. 1, illustratingthestep in its retracted, stowed configuration.

FIG. 3 is a fragmental elevational view taken generally along lines 3-3of FIG. 2.

FIG. 4is a plan view of the step, similar to the plan view of FIG. 2,but illustrating the step in its extended, deployed configuration.

FIG. 5 is a' fragmented, sectioned elevation taken generally along lines5-5 of FIG. 4.

FIG. 6 is a fragmented, sectioned elevation taken generally along lines6-6 of FIG. 2.

FIG. 7 is a schematic view of electrical circuitry employed in extendingand retracting the tread into its stowed and deployed configurations.

DESCRIPTION OF THE INVENTION Referring now to the drawings wherein likereference numerals designate like or corresponding parts throughout theseveral views, there is shown in FIG. 1 a recreational vehicle 10 havinga doorway l2 beneath which is suspended an extensible step 14 embodyingthe principles of the instant invention.

The vehicle 10 is depicted as a mobile home, however, it is to beunderstood that the step 14 has utility with various other types ofunits including campers and house trailers. Furthermore, while the step14 is depicted as being employed from one side of the vehicle 10 it isto be understood that the step can be employed beneath the doorwayregardless of its orientation for accommodating access to the vehicle.

As shown in FIG. 2, the step 14 includes a base frame, generallydesignated 16, adapted to be bolted, welded, or otherwise affixed to thesupporting structure of the vehicle 10. The particular manner in whichthe frame 16 is mounted beneath the vehicle 10 is dictated primarily bythe particular structure available in the vicinity of a doorway 12. Theframe 16 preferably includes a pair of horizontally extended tracks 18for receiving in telescoping fashion a tread assembly, generallydesignated 20.

As best shown in FIG. 3, each of the tracks 18 is of a U-shapedconfiguration and, preferably is fabricated from suitably dimensionedchannel iron. The base frame 16 is suspended by a plurality of hangarbolts 22 passed through a longitudinal beam 24 provided beneath thefloor of the vehicle and extended through an upper lip 26 of each of theU-shaped tracks 18. Depending from the upper lip 26 from each of thetracks 18 is a vertically disposed web 28 which terminates in a lowerlip 30, similar to the lip 28, extended in substantial parallelismtherewith. It is, of course, to be understood that the tracks 18 alsoare arranged in parallelism so that the webs 28 are arranged inparallelism. Thus, the tread assembly is confined at its opposite sidesby the tracks 18 of the base frame 16.

The tread assembly is provided with a pair of parallel rails 32 havingextended therebetween a tread 34 of a substantially planarconfiguration. The tread 34 is extended between the rails 32 and iswelded or otherwise rigidly coupled with the rails so that the rails andthe tread 34 are rigidly integrated to a unitary configuration. Theplane of the tread 34 is angularly related to the plane of the rails 32,as best illustrated in FIGS. 5 and 6, and is of a width substantiallyless than the length of the rails. However, the tread 34 preferably ispositioned adjacent the distal end portions of the rails 32 and issupported along one edge by a transverse bar 36. The bar 36 also isextended between the rails and thus also serves to impart rigidity tothe tread assembly 20. Consequently, it can be appreciated that therails 32, the tread 34, and the bar 36 of the tread assembly 20integrate the tread assembly 20 to a single unit of a rigidconfiguration.

The tread assembly 20 is supported within the base frame 16 by aplurality of roller bearings 38 suitably pinned to the webs 28 of thetracks 18. As best illustrated in FIGS. 5 and 6, the roller bearings 38are appropriately positioned vertically spaced on the webs 28 of thetracks 18 a distance suitable for accommodating a reception of rails 32therebetween. Thus, the tread assembly 20 is supported for rectilinearreciprocation along a substantially horizontal path extending from thebase frame 16. As illustrated in FIG. 6, each of the tracks 18 isprovided with only a pair of roller bearings 38. It should, however,readily be apparent that as many roller bearings 38 as found to bepractical can be provided for supporting the tread assembly 20 withinthe base frame 16, so long as they are appropriately oriented. Theorientation, of course, is such that rails 32 roll on the rollerbearings 38 as'the tread assembly 20 is extended and retracted relativeto the base frame 16.

In practice, each of the rails 32 also is of a U-shaped configurationhaving a pair of substantially coplanar, longitudinally extending lips40, the outer surfaces of which are received by the roller bearings 38.These lips, in turn, are coupled together through a vertical web 42,similar to the web 28. Preferably the lips 40 and web 42 of each of therails 32 are coextensive and terminate at their distal ends in atransverse plate 44 while a transverse plate 46 is provided at theirbase for imparting strength and rigidity to the rails. v

In practice, a skate roller 50 is pinned to each of the webs 28 of thetracks 18 by a bearing pin 42. As best illustrated in FIG. 3, the rails32 and the rollers 50 are plate 46 as the tread assembly 20 is extendedfrom the base frame 16 and thus the rollers 50 effectively serve asstops for arresting the extension of the assembly 20. Furthermore, inview of the fact that only a pair of roller bearings 38 have beenprovided externally of each of the rails 32, each of the skate rollers50 further functions to impart stability to the tread assembly.

As hereinbefore mentioned, the tread 34 is angularly related to therails 32. Thus, in order for the tread 34 to be deployed into anoperative configuration, it is necessary for the rails 32 to assume aninclined disposition, relative to a horizontal plane, upon beingextended from the base frame 16. In order to achieve such an inclinationof the rails 32, each of the rails is provided at its base end with alinear cam surface, generally designated 54.

As illustrated, each of the linear earns 54 includes an inclined plate56, welded or otherwise secured to the base end of one of the rails 32,and is supported by an angular support plate 58 extended from the rail32 to the distal end of the plate 56. The plate 58, of course, also iswelded or otherwise rigidly affixed to the distal end of the rail 32.

As a practical matter, the cam 54 is inclined at an angle slightlygreater than the angle of inclination assumed by the tread 34, so thatonce the rails 32 are extended relative to the base frame 16, the uppersurfaces of the linear cams 54 ride on the uppermost roller bearings 36.When so disposed, the distal ends of the rails 32 are pivoted about theskate rollers 50 and extend downwardly from the base frame 16, so thatthe tread 34 is positioned in a horizontal plane between the floor ofthe vehicle 10 and the ground.

It is to be understood that the lower lips 30 engage the lower surfacesof the rails 32 while the upper lips 26 ingage the upper surfaces of therails 32 as the tread assembly 20 is deployed in its operativeconfiguration. The roller bearings 38 and the skate rollers 50 serve tosupport the tread assembly 20 in its stowed configuration within thebase frame 16. Of course, the skate rollers 50 also limit the outwarddisplacement of the track assebmly 20 relative to the base frame 16.Thus the step 14 is extended into and supported in its operativeconfiguration which facilitates entry into the vehicle l0. As canreadily be appreciated, retraction of the rails 32, for thusrepositioning the tread assembly 20 in its stowed configuration withinthe base frame 16, causes the linear earns 54 to ride along the rollerbearings 38 thereby pivoting the rails 32 about the skate rollers 50 asthe tread assembly is retracted into the base frame 16.

The desired rectilinear motion imparted to the tread assembly 20 as itis extended and retracted is achieved through a drive train, generallydesignated 60. The drive train is powered by a reversible prime mover,preferably an electrically energizable motor'62. The motor 62 is mountedon the base frame 16 in a suitable manner and includes a pinion 64. Thepinion, in turn is driven by gearing mounted in a suitable housing, notdesignated, and is driven by a suitable worm gear, also not designated.

Meshed with the pinion 64 is a gear sector 66 supported for oscillatorymotion by a bearing-supported shaft 68. The shaft 68 is oriented in avertical plane and is supported by suitable bearings mounted in abearing housing 69, FIGS3 and 5. The gear sector 66 preferably is fixedto the drive shaft 68 and thus serves to impart rotation to the driveshaft in response to oscillatory rotation imparted thereto by the motor62, through the pinion 64.

To the uppermost end of the shaft 68 there is affixed a laterallyextended crank arm 70. The crank arm 70 is thus supported for 180 ofthrow as 180 of angular displacement is imparted to the drive shaft 68.At the distal end of the crank arm 70 there is provided a lost motionlinkage 72, including a suitable bearing pin 74 pinned to the distal endof the crank arm 70. The bearing pin 74 rides in an elongated cam slot76, formed in a bracket 77, normally related to the crank arm 70 whenthe arm is in either of its alternate rest positions, assumed as thestep comes to rest in either of its alternate configurations. Thus, thecam slot 76 confines the bearing pin against motion paralleling the pathtraversed by the assembly 20, and yet permits the bearing pin 74 toadvance unrestricted in a direction normal to that path, so that the pin74 imparts rectilinear motion to the bracket 77 as the crank arm 70 isdriven and thus angularly displaced by the shaft 68.

The bracket 77, in turn, is coupled with the transverse beam 36 throughan articulated link 78 fixed at one end to the beam 36 and at itsopposite end to the lost motion linkage 72. As a practical matter, thepivotal link 72 preferably includes a pair of parallel piano hingejoints 80 for accommodating the motion imparted to the base end of thetread assembly as the assembly is reciprocated for alternatelypositioning it in its stowed and deployed configurations.

As best illustrated in FIG. 7, the motor 62 is ener gized by a DC.(direct current) voltage source 82, preferably an automotive batteryfound aboard the vehicle 10. The motor 62 and voltage source 82 arecoupled within an electrical circuit generally designated 83. Thiscircuit includes a manually operable, spring loaded button switch 84 anda pair of limit switches86. The particular circuit through which thelimit switches 86 and the button switch 84 are interconnected is variedas is found practical. However, it is to be understood that the limitswitches 86 each, in turn, deenergize the motor 62 and uponde-energization of the motor, prepare the circuit for a reversedoperation, when it again is energized in response to the closing of thecircuit through the button switch 84. Of course, the button switch 84 islocated at a suitable location aboard the vehicle 10. One such locationis found immediately within the doorway 12 as illustrated in FIG. 1.

In practice, a guide assembly, generally designated 87, is provided forguiding the assembly 20 as it is reciprocated in response to anenergization of the motor 62. In practice, the guide assembly 87includes a pair of guide rods 88 affixed to the bracket 77 of the lostmotion linkage 72 and seated for sliding, telescopic motion within apair of horizontally oriented guide sleeves 90. These sleeves aresecured to the base frame 16 and are employed in imparting lateralstability to the tread assembly 20 as it is reciprocated between itsstowed and deployed dispositions. The guide rods 88 and the sleeves 90thus inhibit binding of the tread assembly 20 within the base frame 16by supporting it against lateral skew. As an additional aid to freedomof movement, and'in maintaining lateral stability, 21 pair of tensionsprings 92 are coupled between the opposite ends of the bar 36' and thebase frame 16 for thus supporting the assembly 20 against skew. Hence,it can be appreciated that the tread assembly 20 is in operationreciprocated without encountering binding resulting from skew.

OPERATION It is believed that in view of the foregoing description theoperation of the device will be readily understood, however, it will bebriefly reviewed at this point.

With the extensible step 14 mounted beneath the doorway 12 of a vehicle10, the tread assembly 20 is extended and retracted relative to the baseframe 16 through a selective manipulation of the button switch 84located within the vehicle 10.

To achieve the desired displacement of the tread assembly 20 anoperator, within the vehicle 10, manipulates the button switch 84 forselectively applying an electrical voltage to the motor 62, from thevoltage source 82. As the motor 62 is energized, the pinion 64 is drivenin rotation for imparting angular displacement to the gear sector 66 forthus energizing the drive train 60. As the gear sector 66 is rotated,the crank arm is caused to sweep an are about the longitudinal axis ofthe drive shaft 68. Due to the effects of the lost motion linkage 72,the sweeping motion of the crank arm 70 is converted to rectilinearmotion for imparting linear motion to the tread assembly 20 along alinear path relative to the base frame 16. The direction of the motionis, of course, dependent upon the direction in which the motor 62 drivesthe pinion 64.

Once the assembly 20 approaches a terminus of its path, the bracket 77of the lost motion linkage 72 simultaneously approaches the terminus ofits path. As this occurs, the switch 86 adjacent thereto is activatedfor interrupting the circuit 83 between the motor 62 and the voltagesource 82. Thus, the motor 62 is deenergized and the motion of the treadassembly 20 is arrested. Once the motor 62 again is energized, throughan appropriate manipulation of the switch 84, a reverse mode ofoperation is imposed on the motor 62 for reversing the direction oftravel of the tread assembly 20 and the bracket 77 of the lost motionlinkage 72.

It will be appreciated, in view of the foregoing, that as the treadassembly 20 is extended from the base frame 16, pivotal motion of thetread assembly occurs about the skate rollers 50 for permitting thetread 34 to drop to its deployed disposition. Likewise, upon aretraction of the tread assembly 20, the cam surfaces 54 pivot the rails32 about the skate rollers 50 for causing the tread 34 to be elevated toa horizontal plane as the tread assembly 20 is retracted into the baseframe In view of the foregoing, it should readily be apparent that theextensible step of the present invention provides a practical solutionto the problem of affording access to vehicles such as campers, mobilehomes, trailers and the like.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the illustrative detailsdisclosed.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. An extensible step for an elevated structure, exemplified by awheel-supported vehicle, comprising:

A. a displaceable tread assembly including a pair of laterally spacedsupport rails disposed in substantial parallelism and a planar treadextended between the rails and rigidly affixed thereto;

B. means for supporting said tread assembly for rectilinearreciprocation along a substantially horizontally oriented path extendedbetween a first location beneath a selected structure and a secondlocation located in outwardly spaced relation with said structure,including a pair of horizontally extended tracks suspended from beneaththe structure for receiving said rails in a supported relationshiptherewith; and

C. drive means for imparting substantially rectilinear motion to saidtread assembly comprising an electrically energizable motor, means forcoupling said motor with said tread assembly including a drive shaftsupported for rotation about an axis orthogonally related to said path,an elongated crank arm having its base rigidly affixed to said shaft andradially extended therefrom, means defining a lostmotion linkage forcoupling the distal end of said crank arm with said tread assembly forimparting linear motion to the tread assembly as rotary mo tion isimparted to said shaft, a gear sector concentrically related to saidshaft and rigidly secured thereto, and gear means connected with saidmotor and meshed with said gear sector for imparting rotary motion tothe gear sector for thereby imparting linear motion to the treadassembly.

2. The extensible step of claim 1 further comprising:

adapted to be mounted beneath the doorway of a recreational vehicle,such as a camper, trailer, mobile home and the like, the improvementcomprising:

A. a substantially rectangular frame having a pair of laterally spacedrails;

B. a tread of a planar configuration extended between said rails andrigidly affixed thereto;

C. a pair of horizontally extended tracks including therein bearingmeans for receiving and supporting said rails for reciprocation in asubstantially horizontally oriented plane; and

D. drive means for imparting horizontally directed, substantiallyrectilinear displacement to said rails, including a drive shaftsupported for rotation about an axis orthogonally related to alongitudinal axis of said tracks, a reversely actuatable prime mover, agear sector fixed to said drive shaft for imparting rotary motionthereto as rotary motion is imparted to the gear sector, gear meansinterconnecting said gear sector with said prime mover, whereby rotarymotion is imparted to the gear sector in response to an activation ofsaid prime mover, a crank arm extended in a substantially radialdirection from said drive shaft, and means including a lost-motionlinkage for coupling the distal end of said crank arm with said frame,whereby said tread is extended and retracted as the prime mover isreversely actuated.

1. An extensible step for an elevated structure, exemplified by awheel-supported vehicle, comprising: A. a displaceable tread assemblyincluding a pair of laterally spaced support rails disposed insubstantial parallelism and a planar tread extended between the railsand rigidly affixed thereto; B. means for supporting said tread assemblyfor rectilinear reciprocation along a substantially horizontallyoriented path extended between a first location beneath a selectedstructure and a second location located in outwardly spaced relationwith said structure, including a pair of horizontally extended trackssuspended from beneath the structure for receiving said rails in asupported relationship therewith; and C. drive means for impartingsubstantially rectilinear motion to said tread assembly comprising anelectrically energizable motor, means for coupling said motor with saidtread assembly including a drive shaft supported for rotation about anaxis orthogonally related to said path, an elongated crank arm havingits base rigidly affixed to said shaft and radially extended therefrom,means defining a lost-motion linkage for coupling the distal end of saidcrank arm with said tread assembly for imparting linear motion to thetread assembly as rotary motion is imparted to said shaft, a gear sectorconcentrically related to said shaft and rigidly secured thereto, andgear means connected with said motor and meshed with said gear sectorfor imparting rotary motion to the gear sector for thereby impartinglinear motion to the tread assembly.
 2. The extensible step of claim 1further comprising: A. control means for said motor including anelectrical circuit having connected therein a source of electricalenergy; and B. switch means interposed in said circuit between saidsource of electrical energy and said motor for interrupting said circuitin response to linear motion imparted to said tread assembly.
 3. In aremotely operated, extensible step of a type adapted to be mountedbeneath the doorway of a recreational vehicle, such as a camper,trailer, mobile home and the like, the improvement comprising: A. asubstantially rectangular frame having a pair of laterally spaced rails;B. a tread of a planar configuraTion extended between said rails andrigidly affixed thereto; C. a pair of horizontally extended tracksincluding therein bearing means for receiving and supporting said railsfor reciprocation in a substantially horizontally oriented plane; and D.drive means for imparting horizontally directed, substantiallyrectilinear displacement to said rails, including a drive shaftsupported for rotation about an axis orthogonally related to alongitudinal axis of said tracks, a reversely actuatable prime mover, agear sector fixed to said drive shaft for imparting rotary motionthereto as rotary motion is imparted to the gear sector, gear meansinterconnecting said gear sector with said prime mover, whereby rotarymotion is imparted to the gear sector in response to an activation ofsaid prime mover, a crank arm extended in a substantially radialdirection from said drive shaft, and means including a lost-motionlinkage for coupling the distal end of said crank arm with said frame,whereby said tread is extended and retracted as the prime mover isreversely actuated.